I've just started helping to raise money for the World Food Programme with SocialVibe. SocialVibe is a network where you can choose a cause and a sponsor, who donates money to your cause depending on the number of points you make.
There are a variety of causes to choose from, related to Hunger & Poverty, Environment, Peace & Human Rights, Animals etc. Once you have chosen what you would like to support, you choose a sponsor from the list given. Finally, you create a badge which you can place on your site or social network pages. You can see mine for WFP below and on the left sidebar.
You get points from people visiting through your badge and from a number of other ways on the site itself. All these points translate into hard cash, which your sponsor donates to your cause. It seems a really great way to raise money, and SocialVibe was the Blogger's Choice Winner, Non-Profit Causes and People's Choice Runner Up, Non-Profit Causes in the 2009 Mashable Open Web Awards.
symposio invites you to SocialVibe.com